Spektrum radios work fine here no matter where you buy it from. The only difference is you have no C-Tick on the radio and you have no warranty if something goes wrong. Spektrum DX3.0 and DX3R are the same price here in Australia as it is on-line, if you include the shipping price. So I would say no, it isn't better to buy it overseas. Any good hobby shop in Sydney will carry the Spektrum line or can order it for you in a day or two.

Take Care,
Cheers, Patrick